This method relates in general to processes for treating crude oils obtained from oleaginous seeds and, more particularly, to a method for treating crude soybean oil to render same of food or commercial grade.
Heretofore crude soybean oil as obtained from soybeans through the practice of the various well known procedures, such as, for instance, those involving solvent extraction or by cold press, has been subjected to what has been popularly referred to as a "degumming" process. The crude oil as subjected to the last mentioned processes is customarily of a relatively dark coloration and contains various solid materials oftentimes collectively referred to as "foots" which may comprise phosphatides, lecithin, proteins, glycerides, and the like, as well as meal and seed remnants. This material is relatively thick and "gummy," having a consistency similar to that of tar. The "degumming" process is designed primarily to make the oil more manageable, as by rendering the same less "gummy," as it were, so that the same may be more easily shipped, as well as being amenable for effective further treatment. Thus, without resorting to a detailed exposition of the degumming process, since such does not constitute a part of the present invention, it may be generally stated that the crude oil is subjected to an elevated temperature as approximating 250.degree. F. and while at such heat is highly centrifuged and with the injection of steam. Subsequent to said process, the treated oil thus has entrained therein substantially reduced amounts of solids and gums which have been in great part removed through the centrifugal action.
The resultant oil may now be treated by the well known esterification method, as with the use of methyl alcohol and distillation so as to appropriately fractionalize the treated material to produce food grade soybean oil. To produce food grade soybean oil from crude soybean oil as provided by the usual extraction processes is a markedly and recognizedly costly one requiring highly complex equipment which consumes valuable plant space and requires the supervision and attendance of highly skilled personnel.
By the present invention the various sequential procedures heretofore deemed requisite for treating crude soybean oil may be entirely eliminated, with attendant substantial saving in both investment in plant and equipment, as well as in cost of production by reason of simplicity of apparatus whereby the same is resistant to breakdown and which obviates the need for the services of highly skilled individuals. Furthermore, by the present invention, substantial saving in time is brought about so that the interval between receiving crude oil and completing treatment of same is most considerably reduced. This invention may be practiced by less affluent firms which have heretofore been caused to ship their crude oil to distant points for refining purposes. Accordingly, such firms, by virtue of the present invention, may now be in the position to sell food grade soybean oil which was hitherto denied them by reason of the particular posture of the pertinent technology.
Another drawback to the processes heretofore known for treating crude soybean oil has been the inadequacy of the same to inhibit rancidification so that the greater the factor the greater the reduction in price.
Therefore, it is an object of the present invention to treat crude soybean oil as produced by well known accepted extraction processes in a fundamentally single step procedure with attendant economy in equipment and in production costs.
It is another object of the present invention to provide a method for treating crude soybean oil as stated by well known, readily available and cheaply acquired agents.
It is a further object of the present invention to provide a method for treating crude soybean oil as described which may be practiced under atmospheric conditions, avoiding the necessity of any carefully controlled environmental conditions; and which does not necessitate the utilization of specially prepared reagents so that no preliminary treatment of the latter is requisite.
It is a still further object of the present invention to provide a method for treating crude soybean oil as stated which does not involve the services of highly skilled, trained individuals, but rather one which may be practiced by an employee with most limited prior instruction.
It is an additional object of the present invention to provide a method for treating crude soybean oil to reduce same to food grade character which in composition and properties is as good as, or better, than food grade soybean oil as provided by techniques and procedures currently known.
It is still another object of the present invention to provide a method for treating crude soybean oil as stated which is equally capable of producing desired by-products concurrently with the production of food grade oil.
Another object of the present invention is to provide a method for treating crude soybean oil which may be performed in a most expeditious, economical manner; which is productive of food grade soybean oil of consistently reliable characteristics and properties; and which, as suggested above, obviates the need for substantial investment in plant equipment and apparatus, as well as consuming costly plant space with attendant necessary fuel costs so that the overall investment for performing the said method is most economic; and which is not a high cost operation so as to be amenable to practice by relatively modest concerns.
In summary, the present invention contemplates the treatment of crude soybean oil by subjection to water and a protein containing compound. The three stated ingredients are then intermixed to present a visually homogeneous body and thereafter permitted to settle for a predetermined period of time. The settlement interval is adequate for the development of sharply delineated strata wherein the uppermost or supernatant layer is constituted of food grade soybean oil. The underlying layers as will be developed more fully hereinbelow are comprised of proteins, water and lecithin. The topmost layer, that is of now food grade oil, is removed by any suitable means, such as by decanting. It has been discovered through analysis that the removed oil may contain some water, as well as possibly some of the treatment material, which latter can be removed through the application of heat. If desired, the oil may be bleached since the coloration of soybean oils is most often determined by the quality of the seeds used.